Food waste disposal system including BOD reduction apparatus

ABSTRACT

The present invention provides a food waste disposal system including a BOD reduction apparatus comprising a concentrated-oxidizing tank, an aeration tank, an air pump and a filter. A drain of food waste disposal system is connected to a inlet of the BOD reduction system. Also, purified water in the BOD reduction system is carried back to a inlet of said food waste disposal system so that purified water is reused in food waste disposal system. A pH sensor, which can measure acidity and basicity, is mounted on a filter drain of the BOD reduction system. When pH of the sensor is less than pH 3, small quantity of caustic soda powder is input from a caustic soda tank mounted on the pipe of the rear end of a water supplying valve of the food waste disposal system to regulate the pH level of food wastewater.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a food waste disposal system comprisinga BOD reduction apparatus installed at the drain of the food wastedisposal system so that food wastewater coming from the food wastedisposal system to be purified and recycled, meeting the sewage qualityrequirement of each country.

2. Description of the Prior Art

Generally, organic waste, such as food waste, contains a large amount offibrous vegetable and animal material, protein, carbohydrates andcalcium. Accordingly, if the organic waste is disposed of as it is in alandfill, without being decomposed, leachate generated from the organicwaste permeates into the soil, resulting in the contamination of groundwater.

Conventional food waste disposal technologies using microbes aredisclosed in Korea Utility Model Publication Nos. 20-1995-5245,20-1995-7541, 20-1995-7395, Korean Patent Laid-Open Publication Nos.20-1994-24804. These technologies are related to methods and apparatusesof fertilizing and composting food waste or organic waste.

The conventional methods and apparatuses can reduce some of the organicmatter in food waste or organic waste, but are insufficient with respectto disposal efficiency and capacity because they take a long period todecompose organic matter and they cannot completely decompose organicmatter. As a result, odors are generated due to the hazardous gasgenerated upon the incomplete decomposition of food waste.

Korean Utility Model No. 20-270982 discloses “Apparatus for DecomposingOrganic Waste”, Korean Patent Laid-Open Publication No. 10-2006-19663discloses “Apparatus for Treating Food Waste”, and Korean Patent No.10-535699 discloses “Structure of Mixing Basin of Apparatus for TreatingFood Waste”.

Korean Utility Model Registration No. 20-20982 discloses “Apparatus forDecomposing Organic Waste”, which comprises a rotational shaft having aplurality of arm blades, installed along a central horizontal line of acell casing provided in a housing, a rotation device which includes agear motor, a driving sprocket, a linking sprocket, and a chain, forrotating the rotational shaft, a hot water tank, and a sprayer with aplurality of spray nozzles, which is installed in an upper part of thecell casing for spraying hot water from the hot water tank into the cellcasing, in which the inner temperature of the cell casing can beadjusted by selectively supplying the hot water from the hot water tank,which is provided with a pre-heater.

Korean Patent Laid-Open Publication No. 10-2006-19663 discloses“Apparatus for Treating Food Waste”, in which food wasted introducedthrough an entrance formed in an upper portion of a treatment basin ispulverized when it passes through a pulverizing mill and falls down, thepulverized food waste is mixed by mixing blades and decomposed, and thenthe decomposed food waste is discharged, in which the treatment basin iscleaned by spraying water using a sprayer installed in an upper portionof the treatment basin.

Korean Patent No. 10-535699 discloses “Structure of Mixing Basin ofApparatus for Treating Food Waste” which comprises an outer casinghaving mixing blades therein, an upper plate which has a drain with ascreen thereon and is fixed to the lower end portion of the outercasing, and a lower plate having a drain in the center portion thereof,which is provided under the upper plate and is integrated with the upperplate, in which food waste introduced through an entrance of the outercasing and onto the upper plate is mixed by the mixing blades, andleachate from the food waste is drained through the screen, flows downto the lover plate, and is then discharged through the drain provided tothe lower plate.

The above-described food waste disposal apparatuses are operated usingmanual switches in an analog manner. Accordingly, they have problems inthat the manipulation thereof is inconvenient and in that they cannot beselectively operated in either an automatic manner or a manual manner.Further, since hot water cannot be supplied into the mixing basin, thefood waste treatment capacity and efficiency thereof are low, and it isdifficult to clean the inside of the cell casing, and thus odors lingeraround the apparatus. Further, since a cleansing device for cleansingthe lower plate, on which leachate collects, is not provided, odorsoccur. Still further, since the mixing basin does not have a leachatedischarge device, leachate overflowing from the cell casing cannot beeasily discharged, so that the apparatus cannot be smoothly operated.

In order to overcome the disadvantage of problems above, U.S. Pat. No.7,735,761 and U.S. Pat. No. 7,762,713 to the inventor discloses a foodwaste disposal system by putting microbes during a process of drying thefood waste, comprising a mixing basin installed in a housing, and arotational shaft with a plurality of mixing blades.

Although the food waste disposal system of U.S. Pat. No. 7,735,761 andU.S. Pat. No. 7,762,713 have resolved the prior art's drawbacks, in theprocess that the leachate produced by the microbe's biologicaldecomposition goes to drain or sewer system with cleansing water, it ishard to maintain the quality of waste water so as to satisfy theenvironmental regulation proposed by the countries and in the worstcase, the food waste disposal system is banned to use in some countries.To overcome this issue, there needs an additional device attached to thefood waste disposal system, which improves the waste water quality tomeet the each countries' environmental requirement.

Also, there is a large amount of water required to discharge thedecomposed food waste to the drain. Normally, to maintain the supportiveenvironment inside the mixing basin for effective decomposition processof food waste, water supply function which provides the moisture insidethe mixing basin, and discharge function which provides the cleansingthe washing chamber, these two functions are operated in every cycle atthe operation of the food waste disposal system. The usage of water fortwo functions consumes 4 liter per cycle, and when summed up to dailyusage, water required per day goes up to 400 liters. The fact that thesubstantial amount of water usage discourages the user to operate thefood waste disposal system environmentally friendly, thus the moreeffective water usage system that uses less water should be considered.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems with an object to provide an improved food waste disposalsystem with the BOD reduction system, comprising of aconcentrated-oxidizing tank, an aeration tank, a filter and an air pump.Influent food wastewater which contains food residuals discharged fromthe food waste disposal system enters the concentrated-oxidizing tankthrough an inflow pipe and is stored in the tank for several days.Subsequently, in the tank, the food wastewater is mixed with airsupplied from an air pump and oxidized by aerobic bacteria. The influentfood wastewater discharged from the concentrated-oxidizing tank is mixedwith activated sludge in the aeration tank which facilitates theabsorption and oxidative decomposition of organic matter by supplyingoxygen via the air pump. The influent food wastewater purified in theaeration tank is filtered through different layers of sand, gravel,granule gravel, charcoal and glass wool. The air pump works to supplyair to the concentrated-oxidizing tank and the aeration tank.

The food wastewater discharged from the food waste disposal system flowsinto the BOD reduction system, and pipe connections are made so that thewater purified in the BOD reduction system flows back into the foodwaste disposal system.

According to an embodiment of the present invention, the oxidizingaeration tank comprises two chambers—the first aeration chamber and thesecond aeration chamber. The first aeration chamber receives influentfood wastewater from the concentrated-oxidizing tank through aconnecting pipe. It is equipped with a fixed media and a disc rubberdiffuser which allows aeration to occur when oxygen flows into the tankby blowing air in through an air pipe from the outer air pump. Thesecond aeration chamber is equipped with a plate-type media and amembrane diffuser which allows aeration to occur when oxygen flows intothe tank by blowing air in through an air pipe from the outer air pump.

According to an embodiment of the present invention, the BOD reductionsystem has the concentrated-oxidizing tank in front and the oxidizingaeration tank in back and provides space where a filter will beinstalled on the right side of the oxidizing tank, the width (W1) ofwhich is to be one half of the aeration tank's width (W0). The filter isset up in the space on the right of the oxidizing tank, and the totalwidth of the filter area is not to be greater than the aeration tank'swidth (W0). The air pump is placed between the oxidizing tank and theaeration tank and thus the BOD reduction system features an overallsquare-shaped arrangement with side length equal to the oxidizing tank'swidth (W0).

According to an embodiment of the present invention, the BOD reductionsystem's concentrated-oxidizing tank, aeration tank and filter areconnected to each other by connecting pipes, and the connecting pipesremain adjusted to specific heights so that the next process canautomatically start when the influent food wastewater reaches a certainlevel (H1 or H2).

According to an embodiment of the present invention, the filter has highand low water level sensors on its upper and lower parts and the lowwater-level sensor serves to detect the volume of purified water so thatwater volume is maintained at more than a certain level. The waterpurified by the filter is sent back to the food waste disposal system,supply recycled water to the water supplying cycle.

According to an embodiment of the present invention, the food wastedisposal system comprises a water supplying valve which opens and closesthe water supply from waterworks; a water supplying pump which pumpswater supplied from the water supplying valve into the mixing basin; adischarge valve which is opened or closed by the Programmable LogicController (PLC) for water supplied from waterworks to be drawn into thewashing chamber's discharging water supply nozzle; a caustic soda tankvalve which opens and closes the feed for caustic soda stored in thecaustic soda tank; a reusable water supplying valve which is opened orclosed by the PLC for supply of water purified in the BOD reductionsystem's filter; high and low water level sensors which work to detectthe water levels of the BOD reduction system's filter; a pH sensor setup in the filter drain to measure acidity and basicity; a final drainvalve set up in a final drain; and the PLC which firstly controls thecaustic soda tank valve allowing caustic soda to be put in water pumpedby the water supplying pump based on a pH sensor-detected pH value,secondly enables the supply of purified water by opening the reusablewater supplying valve with the water supplying valve closed and thirdlyopens the final drain valve when a high-level signal is input from thehigh water level sensor.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a perspective view showing an installation example ofthe food waste disposal system equipped with a BOD reduction systemaccording to one embodiment of the present invention.

FIG. 2 illustrates a schematic diagram showing the configuration of theBOD reduction system according to one embodiment of the presentinvention.

FIG. 3 illustrates a plan view showing an optimal installation of theBOD reduction system according to one embodiment of the presentinvention when it has been actually installed.

FIG. 4 illustrates piping diagrams of the food waste disposal system andBOD reduction system according to one embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The above-described objects, advantageous effects and features of thepresent invention will be apparent from the following description withreference to the accompanying drawings.

FIG. 1 illustrates a perspective view showing an installation of thefood waste disposal system equipped with a BOD reduction systemaccording to one embodiment of the present invention.

The food waste disposal system equipped with a BOD reduction systemunder this invention comprises a food waste disposal system unit 100 anda BOD reduction system 200 which works to ferment and decompose foodresiduals contained in sewage drained from the food waste disposalsystem unit 100.

The food waste disposal system unit 100 under this invention is the sameas the food waste disposal system posted U.S. Pat. No. 7,735,761, U.S.Pat. No. 7,762,713 and U.S. application No. 13304516 by the sameinventor of this application, so the detailed description thereof willbe left out.

A connecting pipe 21 a that carries the food wastewater discharged fromthe food waste disposal system 100 under this invention is connected tothe inlet of the BOD reduction system 200, and pipe connections are madefor water purified in the BOD reduction system 200 to be carried back tothe inlet of food waste disposal system 100 and thus be reusable in thefood waste disposal system 100.

The BOD reduction system 200 under this invention comprises four mainparts: a concentrated-oxidizing tank 21, an aeration tank 22, an airpump 23 and a filter 24.

FIG. 2 illustrates a schematic diagram showing the configuration of theBOD reduction system according to one embodiment of the presentinvention.

The BOD reduction system 200 under this invention comprises theconcentrated-oxidizing tank 21 which receives food wastewater containingfood residuals discharged from the food waste disposal system 100through the connecting pipe 21 a. In this tank, the influent foodwastewater is stored for several days and mixed with air supplied fromthe air pump 24, and then oxidized by aerobic bacteria. After the inflowof influent food wastewater into the concentrated-oxidizing tank 21,wastewater and nitrogen and phosphorus are removed from the wastewaterand suspended solids and other residues are filtered out of it byfluidized media where microorganisms are attached and grow.

The influent food wastewater purified first in theconcentrated-oxidizing tank 21 flows into the aeration tank 22 whichcomprises the first aeration chamber 22 a and the second aerationchamber 22 b. The first aeration chamber 22 a receives the influent foodwastewater from the concentrated-oxidizing tank above 21 via aconnecting pipe 21 c equipped with a valve 21 b, and the received foodwastewater goes through the first fermentation process inside the firstaeration chamber 22 a.

The first aeration chamber 22 a is equipped with a plurality of fixedmedia 22 c. If air is blown into the chamber through an air pipe 24 afrom the outer air pump, oxygen flows into the tank through the discrubber diffuser 221 and such inflow of oxygen causes aeration.

The second aeration chamber 22 b is equipped with a plurality ofplate-type media 22 d. If air blown into the chamber through the airpipe 24 a from the outer air pump 24, oxygen flows into the tank throughthe membrane diffuser 222 and such inflow of oxygen leads to an aerationprocess.

The oxidizing aeration tank 22 contributes to efficient purification ofinfluent food wastewater by allowing food residuals in the wastewater tobe further decomposed while going through an oxidation process andallowing food residuals to be continuously filtered out by media (22 c,22 d).

In the aeration tank 22, decomposed precipitates settle down to thebottom but can be later discharged through a maintenance process. Theinfluent food wastewater purified in the aeration tank 22 is filtered bythe filter 23 for the last time.

The filter 23 is equipped with gravel and activated carbon filter units,and food residuals are filtered out and purified to the end when waterthrough the filter. It is recommended to replace the filter 23 everythree months for effective filtering.

Once influent food wastewater has passed through all the treatment andfiltration processes in the concentrated-oxidizing tank, aeration tankand filter as described above, its BOD will be reduced to about 1000lower in values than that of food wastewater when discharged at firstfrom the food waste disposal system 100.

FIG. 3 illustrates a plan view showing an optimal installation of theBOD reduction system according to one embodiment of the presentinvention when it has been actually installed.

As illustrated, the BOD reduction system 200 under this invention hasthe concentrated-oxidizing tank 21 in front and the aeration tank 22 andprovides space for filter installation 23 on the right side of theconcentrated-oxidizing tank 21, the width (W1) of which is to be onehalf of the aeration tank's 22 (W0).

The filter 23 is set up in the space on the right of theconcentrated-oxidizing tank 21, and the total width of the filter is notto be greater than the aeration tank's 22 width (W0). The air pump 24 isplaced between the concentrated-oxidizing tank 21 and the aeration tank23, and thus an overall square-shaped arrangement is made with sidelength equal to the aeration tank's 22 width (W0).

Like this, the BOD reduction system 200 under this invention is designedto minimize the size of the unit and thus installation space by placingthe concentrated-oxidizing tank 21, the aeration tank 22, the filter 24and the air pump 24 in proper positions.

As illustrated in FIG. 2, the concentrated-oxidizing tank 21, theaeration tank 22 and the filter 24 are connected to each other byconnecting pipes (21 c, 220, and they (21 c, 22 f remain adjusted tospecific heights so that the next process can automatically start whenthe influent food wastewater reaches a certain level (H1 or H2).

For maintenance purposes, a manual valve 25 is mounted on the finaldrain 23 d of the filter 23, and thus purified water can be selectivelydrained by opening or closing the manual valve 25.

FIG. 4 illustrates piping diagrams of the food waste disposal system andBOD reduction system according to one embodiment of the presentinvention and a circuit diagram showing how individual valves andcontrollers are connected.

A piping diagram provides an explanation of how the water purified bythe BOD reduction system 200 is reused in the food waste disposal system100.

The food waste disposal system 100 under the present invention comprisesa water supplying valve 101 which opens and closes the water suppliedfrom waterworks; a water supplying pump 107 which pumps water suppliedfrom the water supplying valve 101 into the mixing basin's 102-1 watersupply nozzles 102 a; a discharge valve 108 which is opened or closed bythe PLC 106 for water supplied from waterworks to be drawn into awashing chamber's 102-2 discharging water supply nozzles 102 b; acaustic soda tank valve 109 which opens and closes the feed for causticsoda stored in the caustic soda tank 105; a reusable water supplyingvalve 104 which is opened or closed by the PLC 106 for supply of waterpurified in the BOD reduction system's 200 filter 23; high and low waterlevel sensors (23 b and 23 c) which work to detect the water levels ofthe BOD reduction system's 200 filter 23; a pH sensor 202 set up in afilter drain 23 a of the filter 23 to measure acidity and basicity; afinal drain valve 201 set up in a final drain 23 d; and the PLC 106which firstly controls the caustic soda tank valve 109 allowing causticsoda to be put in water pumped by the water supplying pump 107 based ona pH sensor-detected pH value, secondly enables the supply of thepurified water by opening the reusable water supplying valve 104 withthe water supplying valve 101 closed and thirdly opens the final drainvalve 201 when a high-level signal is input from the high water levelsensor 23 b.

For the food waste disposal system 100, basically piping is designed inorder for water to be supplied from a water supply line (waterworks) ina building. The water line of the food waste disposal system 100 isdivided into two lines for the following functions: water supplyingfunction operated by the water supplying valve 107 and the dischargingfunction operated by the discharge valve 108. Both functions spray waterthrough the spray nozzles (102 a, 102 b). The water supply function isperformed through the water supplying pump 107 and the dischargingfunction through the discharging valve 108. At this time, the originalwater pressure existing in the water supply line of the waterworks isused.

The filter drain 23 a is connected to the water line between the watersupply valve 101 and the water supply pump 107. A reusable watersupplying valve 104 is installed between the water supply function lineand the filter drain 23 a of the BOD reduction system 200, which isopened by PLC 106. Therefore, the purified water in the BOD reductionsystem 200 is supplied to the food waste disposal system for reuse.

The purified water in the BOD reduction system 200 is recycled only forthe water supplying function because the water should be pumped tomaintain enough pressure to be sprayed through the nozzle. There is nopumping device in the discharging function line and all the purifiedwater from the BOD reduction system 200 is sent to water supplyingfunction.

Given below is an explanation of the operation of the food wastedisposal system equipped with the BOD reduction system under thisinvention.

Once the food waste disposal system 100 is in operation mode, the watersupplying valve 101 is opened and water is sprayed into the mixing basin102-1. Then, a plurality of mixing blades rotates to mechanicallyagitate the food waste and the microorganism seeded inside of the mixingbasin 102-1 starts to biologically decompose the food waste.

The residues that are generated while food waste is decomposed passthrough a plurality of perforation formed at the bottom of the mixingbasin 102-1 and then, collected in the washing chamber 102-2. Thedischarging valve 108 is opened to cleanse them out so that the foodwastewater is discharged out to the drain 110 of the food waste disposalsystem 100.

In the process that food waste is decomposed, water flows out throughthe drain 110, in which the residues of the decomposed food waste aremixed. This food wastewater goes into the sewage system in a building,but in this case, the quality of water may not meet the standardsregulated by each country. It is one of the biggest challenges tocontrol BOD level, which is one of the most important standards forsewage water quality. In order to resolve this matter, the BOD reductionsystem 200 is connected to the drain 110 of the food waste disposalsystem 100 through the connecting pipe 21 a. Once the food wastewaterflows into the BOD reduction system 200, it goes through theconcentrated-oxidizing process in the first concentrated-oxidizing tank21, and it passes through the first aeration chamber 22 a and the secondaeration chamber 22 b. In this process, most of solid and floatingmatters are decomposed. Finally, the sewage goes through the filter 23and becomes purified.

On the upper and the lower part of the filter 23, high and low waterlevel sensors (23 b and 23 c) are installed so the quantity of purifiedwater is sensed. Once particular quantity of water is collected, thepurified water is supplied through the water supplying cycle. To use thepurified water in the food waste disposal system 100, the watersupplying valve 101 remains closed and the reusable water supplyingvalve 104 opens instead.

The water purified in the BOD reduction system 200 is mainly used forthe water supplying function so the quantity of water consumed from thewaterworks by the food waste disposal system 100 can be remarkablyreduced. In order to maintain the favorable condition inside the mixingbasin 102-1 of the food waste disposal system 100, the water reused forabout 10 cycles won't be used again and instead, it will be alldischarged to sewage system in the building by the final drain valve201.

So, the final drain valve 201 is open to discharge all the water in thefilter 23 after 10 time use of recycled water. After all the water isdischarged, new cycle starts from the initial process.

In case when the cycle frequency of discharging function is increased,the quantity of water flowing into the filter could be more than thequantity of water reused for the water supplying function and possiblycauses overflow problem in the filter 23. In order to cope with thissituation, the high water level sensor 23 b is mounted in the tank ofthe filter 23. Therefore, once the quantity of water exceeds the heightof the high water level sensor 23 b, the final drain valve 201immediately opens and discharges all the water collected in the filter23 to prevent the overflow of purified water.

The pH sensor 202, which can measure acidity and basicity, is mounted onthe filter drain 23 a of the filter composing the BOD reduction system200. When pH of the sensor is less than pH 3, small quantity of causticsoda powder is input from the caustic soda tank 105 mounted on the pipeof the rear end of the water supplying valve 101 of the food wastedisposal system 100.

The conditions of the mixing basin 102-1 are likely to be acidified whenfood waste is decomposed by microorganisms and the food wastewater afterthe decomposition process also becomes acidified when drained out.

In actual case, the pH value of the food wastewater coming from the foodwaste disposal system 100 is always lower than pH 7. So, only the basicsubstance is necessary for neutralizing acidified food wastewater beforegoing to be drained. In order to input caustic soda powder, the causticsoda tank 105 is installed on the pipe. Based on the pH value sensed bythe pH probe sensor 202, it is possible to adjust acidity and basicityof the final food wastewater by adding caustic soda to the supplyingwater.

According to the present invention, the BOD level of the food wastewaterfrom the food waste disposal system is improved as a BOD reductionsystem installed. Also, the pH sensor and caustic soda tank areinstalled to improve pH levels so that the food wastewater qualitystandard of each country can be satisfied. Further, the purified wateris reusable in the food waste disposal system and accordingly the amountof water to be used in the food waste disposal system is significantlyreduced. All this makes the equipment under this invention to be moreenvironmentally friendly.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A Food waste disposal system including a BODreduction system comprising: a. a concentrated-oxidizing tank whichreceives a food wastewater containing food residuals discharged fromsaid food waste disposal system through a connecting pipe and theinfluent food wastewater is stored for several days and mixed with airsupplied from an air pump, and then oxidized by aerobic bacteria; b. aaeration tank in which the influent food wastewater initially purifiedin said concentrated-oxidizing tank goes through the fermentationprocess; c. a filter which contains different layers of sand, gravel,granule gravel, charcoal and glass wool; d. an air pump which works tosupply air to said concentrated-oxidizing tank and said aeration tank;wherein said concentrated-oxidizing tank, said aeration tank and saidfilter are connected to each other by connecting pipes and the height ofsaid connecting pipes remain adjusted so that the next process canautomatically start when the influent food wastewater reaches a certainlevel, and wherein a drain of said food waste disposal system isconnected to a inlet of said BOD reduction system and purified water insaid BOD reduction system is carried back to a inlet of said food wastedisposal system so that purified water is reused in said food wastedisposal system.
 2. A Food waste disposal system including a BODreduction system according to claim 1, wherein said aeration tankcomprises a first aeration chamber and a second aeration chamber andsaid first aeration is equipped with a plurality of fixed media and adisc rubber diffuser to flow in oxygen from said air pump and saidsecond aeration chamber is equipped with a plurality of plate-type mediaa membrane diffuser to flow in oxygen from said air pump.
 3. A Foodwaste disposal system including a BOD reduction system according toclaim 1, wherein said concentrated-oxidizing tank is located in frontand said aeration tank in the back, providing space for said filter onthe right side of said concentrated-oxidizing tank, the width of whichis to be one half of said aeration tank's and said filter is set up inthe space on the right of said concentrated-oxidizing tank, and thetotal width of said filter is not to be greater than said aerationtank's width so that said air pump is placed between saidconcentrated-oxidizing tank and said aeration tank, thus an overallsquare-shaped arrangement is made with side length equal to saidconcentrated-oxidizing tank's width.
 4. A Food waste disposal systemincluding a BOD reduction system according to claim 1, wherein, on theupper and the lower part of said filter, a high water level sensor and alow water level sensor are installed so the quantity of purified wateris sensed by said low water level sensor and once particular quantity ofwater is collected, the water is reused to water supplying functioncycle in said food waste disposal system.
 5. A Food waste disposalsystem including a BOD reduction system according to claim 1, furthercomprising: a. a water supplying valve which opens and closes the watersupply from waterworks; b. a water supplying pump which pumps watersupplied from said water supplying valve into a mixing basin; c. adischarge valve which is opened or closed by a Programmable LogicController (PLC) for water supplied from waterworks to be drawn into awashing chamber's discharging water supply nozzle; d. a caustic sodatank valve which opens and closes the feed for caustic soda into a waterline of said food waste disposal system; e. a reusable water supplyingvalve which is opened or closed by said PLC for supply of purified waterin said BOD reduction system's said filter; f. a pH sensor set up in afilter drain to measure acidity and basicity; g. a final drain valve setup in a final drain; wherein said PLC firstly controls said caustic sodatank valve allowing caustic soda to be put in water pumped by said watersupplying pump based on a pH sensor-detected pH value, secondly enablesthe reuse of purified water by opening said reusable water supplyingvalve with said water supplying valve closed and thirdly opens saidfinal drain valve when a high-level signal is input from said high waterlevel sensor.